Kinetics of the dehydration of calcium oxalate trihydrate crystals in aqueous solution

Gardner, G.L.

doi:10.1016/0021-9797(76)90308-8

Cited by 40 publications

(10 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Calcium oxalate monohydrate (whewellite) and dihydrate (weddellite) together with calcium phosphate (hydroxyapatite) are the major components of most of the urinary calculi [1,2]. Calcium oxalate trihydrate has been rarely found in kidney stones [3], but it might be important as a possible precursor in their formation [4,5].…”

Section: Introductionmentioning

confidence: 99%

Solubility of the Three Calcium Oxalate Hydrates in Sodium Chloride Solutionsand Urine-Like Liquors

Streit

Tran‐Ho

Königsberger

1998

Monatshefte fuer Chemie

View full text Add to dashboard Cite

Calcium oxalate forms three hydrates (stable monoclinic mono-hydrate (COM), metastable tetragonal dihydrate (COD) and triclinic trihydrate (COT)), which are of medical importance in urinary calculi formation. In this work, the solubility of these calcium oxalate hydrates was determined at 20, 25, 30, 37, and 40 C in aqueous NaCl (0.02±0.20 mol Á dm À3 ) and in urine-like liquors. Also, for the ®rst time, the solubility of COM was systematically studied as a function of pH in arti®cial urine solutions which contain organic compounds. The concentrations of calcium ions were measured continuously using a calcium ion selective electrode and also determined by AAS. The thermodynamic solubility products were obtained from computer simulations in which all possible complexes formed in aqueous solution were taken into account. These values were compared to those available in the literature; it was found that the present results, especially for COD and COT, constitute a major improvement on the previously reported values. The constants determined in this work were used to predict the solubility of calcium oxalate hydrates at different pH in urine-like liquors. It was found that in arti®cial urine solutions, citrate and magnesium ions promote the solubility of COM, whereas urea and creatinine have no signi®cant effect. Lo Èslichkeit der drei Calciumoxalathydrate in Natriumchloridlo Èsungen und urina Èhnlichen Flu È ssigkeiten Zusammenfassung. Calciumoxalat bildet das stabile monokline Monohydrat (COM) sowie zwei metastabile Phasen, das tetragonale Dihydrat (COD) und das trikline Trihydrat (COT). Da die drei Calciumoxalathydrate bei der Entstehung von Nierensteinen eine wichtige Rolle spielen, wurde ihre Lo Èslichkeit bei 20, 25, 30, 37, und 40 C in NaCl-Lo Èsungen (0.02±0.20 mol Á dm À3 ) sowie in ku Ènstlichen Urinlo Èsungen, die zum Teil auch organische Substanzen enthielten, gemessen. In letzteren wurde die Lo Èslichkeit von COM als Funktion des pH-Werts erstmalig systematisch untersucht. Die Ca 2 -Konzentrationen wurden mit Hilfe einer ionenselektiven Elektrode sowie durch AAS bestimmt. Die thermodynamischen Lo Èslichkeitsprodukte wurden aus Computersimulationen erhalten, in denen die in der wa Èûrigen Lo Èsung vorkommenden Komplexe weitestgehend Ã Corresponding author beru Ècksichtigt wurden. Beim Vergleich dieser Gro Èûen mit Literaturwerten stellte sich heraus, daû insbesondere die Werte fu Èr COD und COT eine wesentliche Verbesserung gegenu Èber den bisherigen Daten darstellen. Die in dieser Arbeit ermittelten Lo Èslichkeitsprodukte wurden zur Berechnung der Lo Èslichkeit der Calciumoxalathydrate in ku Ènstlichem Urin verwendet. Es zeigte sich, daû Mg 2 und Citrat die Lo Èslichkeit erho Èhen, wogegen Harnstoff und Creatinin keine signi®kante Auswirkung haben.

show abstract

Section: Introductionmentioning

confidence: 99%

Solubility of the Three Calcium Oxalate Hydrates in Sodium Chloride Solutionsand Urine-Like Liquors

Streit

Tran‐Ho

Königsberger

1998

Monatshefte fuer Chemie

View full text Add to dashboard Cite

show abstract

“…The activation energies for the two step dehydration reactions were calculated to be 87.9 kJ mol -1 (for -2 H 2 O dehydration) and 105.3 kJ mol -1 (for -H 2 O dehydration) and the corresponding change of enthalpy was 573 and 289 J g -1 , respectively. The dehydration of COT to the thermodynamically stable monohydrate form has also been studied in aqueous solutions at various supersaturations in the temperature range of 25-40°C [35]. It has been found that the solid state nucleation and growth of COM takes place after the macroscopic growth and agglomeration of the trihydrate crystals occurs.…”

Section: Introductionmentioning

confidence: 99%

“…It has been found that the solid state nucleation and growth of COM takes place after the macroscopic growth and agglomeration of the trihydrate crystals occurs. The concluding processes probably involve solution growth and ageing of the newly formed monohydrate crystals and the overall dehydration process has an approximate activation energy of 188 kJ mol −1 [35].…”

Section: Introductionmentioning

confidence: 99%

Kinetic study of dehydration of calcium oxalate trihydrate

Honcová

Svoboda

Pilný

et al. 2015

J Therm Anal Calorim

View full text Add to dashboard Cite

The dehydration of calcium oxalate trihydrate was studied using DSC method and open sample crucibles. The dehydration proceeds in two steps where first two molecules of water are released around 80 °C and consequently the last molecule of water is released at a temperature around 130 °C. The kinetic analysis of overlapping peaks was done and the apparent activation energy, pre-exponential factor and kinetic exponents of kinetic model (reaction order model) were evaluated for both effects.

show abstract

“…Still other solvates are stable only below room temperature or have so far been found only to be metastable over the range studied. [3][4][5][6][7][8][9][10][11][12] These show that a solvate does not necessarily have to be the most stable form in its solvent at any temperature. The general trend is that hydrate stability is a function of temperature; this relationship has been alluded to in various works [13][14][15][16] and stated more clearly by Black et al 17 Based on these works, the following rule is emphasized:…”

Section: Introductionmentioning

confidence: 99%

A Thermodynamic-Based Approach to Analyzing a Highly Solvating Polymorphic System: The Desolvation Window Method

Samas

Seadeek

Campeta

et al. 2011

Journal of Pharmaceutical Sciences

View full text Add to dashboard Cite

Kinetics of the dehydration of calcium oxalate trihydrate crystals in aqueous solution

Cited by 40 publications

References 14 publications

Solubility of the Three Calcium Oxalate Hydrates in Sodium Chloride Solutionsand Urine-Like Liquors

Solubility of the Three Calcium Oxalate Hydrates in Sodium Chloride Solutionsand Urine-Like Liquors

Kinetic study of dehydration of calcium oxalate trihydrate

A Thermodynamic-Based Approach to Analyzing a Highly Solvating Polymorphic System: The Desolvation Window Method

Contact Info

Product

Resources

About